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Common Side Effects of Probiotics

Updated: Mar 9, 2023

If you have IBS or other digestive issues, taking a probiotic supplement or eating fermented, probiotic rich foods seems like the logical next step. You may have been recommended this by a doctor or nutritionist. However, probiotics can sometimes make things worse when used straight away for a lot of people with significant gut dysfunction or dysbiosis, and don’t always work. This post will shed some light on why probiotics sometimes make your symptoms worse and what to do about it.

Here’s what we’re going to cover:

  • The benefits of probiotics.

  • The most common side effects of probiotics.

  • Why probiotics can make your symptoms worse.

  • How to pick a probiotic supplement.

  • How to titrate your dose to minimise IBS symptoms from probiotics.

What are probiotics

According to the WHO’s definition, Probiotics are live microorganisms, typically bacteria or yeast, that give us health benefits when ingested in sufficient amounts. The most common species that we see in our supplement probiotics are strains of bifidobacterium and lactobacillus. Probiotics have many potential health benefits including:

  • supporting immune system

  • improving digestive function

  • increasing absorption of nutrients

  • preventing and treating UTIs

  • reducing symptoms of IBS and IBD

It’s important to note that most probiotics don’t colonise the gut i.e. set up shop and live there. They pass through the GI tract and play useful roles along the way, and help existing colonies of beneficial bacteria to grow and proliferate.

Most common side effects of probiotics

Despite their proven health benefits (for those who tolerate them really well), for those who don’t tolerate them, the most common side effects of probiotics are:

  • Gas

  • Bloating

  • Looser stools

  • Abdominal pain

For most people, these side effects are short lived and just take a week or so of adjusting to introducing new bacteria.

Why probiotics can make you feel worse

Your microbiome, which is made up of trillions of different microorganisms and their genetic material, likes to live in harmony and balance. Which is why introducing different types through probiotics can temporarily have an impact on the balance and the symptoms we experience.

Even though we ultimately want to change the current balance of your microbiome, there may be an adjustment period as your body gets used to your new norm. When supplementing with probiotics, the level of equilibrium that did exist is temporarily disrupted. It’s not until a hopefully more beneficial balance is reached that you will begin to see the benefits of probiotics.

If you do have a temporary reaction to probiotics, in most cases, this doesn’t mean it’s doing any harm, and in fact it can usually be interpreted as a good thing (although uncomfortable for you).

When to push through and when to change strategies

If you take a probiotic and notice some symptoms pop up or get worse, try to continue for a week (unless very severe). If you’re still experiencing symptoms and they are not improving, or getting worse, it’s best to stop the probiotic and focus on identifying and treating the root issue of your GI symptoms (more on this below).

If you notice your symptoms improving after 1 week or less, or your symptoms are mild and manageable, continue with the probiotic.

In my clients, I would push through any initial discomfort with those who have mild dysbiosis and no diagnosed overgrowths or pathogens. For those with diagnosed overgrowths or pathogens, it’s best to deal with this first and start probiotics later.

How to choose a probiotic supplement

A reaction to probiotics may be more to do with the specific product you are using and not so much with probiotics in general. Here are three things you need to consider when choosing a good quality probiotic:

> Effectiveness of strains - some strains are more well researched than others, and they all have various uses, so chat with your practitioner on what’s right for your condition.

> Survival rate - While some strains of probiotics are shown to survive conditions like the inside of your stomach, others are not so lucky. Therefore it’s important that the brand you choose has taken this into account by guaranteeing their product will survive stomach acid. I like to use spore based probiotics with my clients as they have high survival rates and are often well tolerated.

> Reputable brand - with probiotics not being regulated in many markets, ensuring you’re getting what you pay for can be difficult. For this reason, I recommend sticking with reputable brands recommended by your practitioner.

> Avoid fillers - Many store-bought probiotics contain ingredients that can aggravate symptoms for some people, including; D-lactate-forming species like Lactobacillus acidophilus, or tapioca and potato starch, maltodextrin, lactose, inulin, pectin as well as other prebiotics that may cause issues.

Working out the right probiotic for you, if you have IBS or other gut health issues, can be a complex process. Working closely with your practitioner and considering functional lab results, health history and any previous side effects of probiotics or probiotic-rich foods is a great way to ensure you’re onto the right strains for your healing journey.

Titrate probiotics in slowly to minimize side effects

To avoid any potential side effects of probiotics, I recommend introducing probiotics in slowly. Titrating in gradually is particularly relevant for higher strength products. This often means breaking open a capsule and sprinkling out a small amount before building up to a more standard dosage. By titrating slowly, you’ll typically avoid any major reactions and will be able to reduce the dosage to the last tolerated amount. Once your body is comfortable, you can slowly increase the dosage.

Get Functional GI Lab Testing

If you find that you experience side effects of probiotics or eating probiotic-rich foods, even after using a high quality product recommended by your practitioner, titrating them in slowly and persisting for at least a week, then functional GI testing is definitely recommended.

The inability to tolerate probiotics is a common sign of gut pathogens like parasite and bacterial infections, as well as bacterial and yeast overgrowths like SIBO. For this reason, and because each condition requires separate treatment approaches, functional GI lab testing is key to working out exactly what is going on in your gut.

For those who don’t tolerate probiotics, I’d definitely recommend a comprehensive stool test and a SIBO breath best as a good place to start.

If you want to learn more about the testing process, or how I can help, please book a free 20 minute introductory consultation here.

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